Differentiation of inflammatory papulosquamous skin diseases based on skin biophysical and ultrasonographic properties: A decision tree model.

BACKGROUND: The biophysical and ultrasonographic properties of the skin change in papulosquamous diseases. AIMS: : To identify biophysical and ultrasonographic properties for the differentiation of five main groups of papulosquamous skin diseases. METHODS: Fifteen biophysical and ultrasonographic parameters were measured by multiprobe adapter system and high-frequency ultrasonography in active lesions and normal control skin in patients with chronic eczema, psoriasis, lichen planus, pityriasis rosea and parapsoriasis/mycosis fungoides. Using histological diagnosis as a gold standard, a decision tree analysis was performed based on the mean percentage changes of these parameters [(lesion-control/control) ×100] for differentiation of the diseases. RESULTS: The accuracy of the decision tree model for differentiation of five diseases was 67% which developed based on changes in stratum corneum hydration, epidermal thickness, skin pH, melanin index, R0 (reciprocal of firmness) and erythema. Among the flowcharts for pairs of diseases, three models for differentiation had high accuracy (> 95%): those of psoriasis from lichen planus, pityriasis rosea, and parapsoriasis/mycosis fungoides. LIMITATIONS: Validation studies on a larger sample size in situations where the diagnosis is unclear are needed to confirm the accuracy and applicability of decision trees. CONCLUSION: Skin biophysical and ultrasonographic properties may help in the differentiation of papulosquamous diseases as simple and non-invasive tools.

Schwann cells as underestimated, major players in human skin physiology and pathology.

Schwann cells (SCs) have long been recognized for their ability to support repair and promote axon regeneration following injury to the peripheral nervous system. In response to nerve injury, they rapidly dedifferentiate into a precursor-like state, secrete an array of inflammatory mediators and growth factors, proliferate, undergo epithelial-to-mesenchymal-like transformation to facilitate migration, phagocytose cellular debris and remodel the extracellular environment to promote regeneration of axons through the site of injury. However, even though a cutaneous role for SCs is becoming increasingly recognized, we argue in this Viewpoint essay that the likely complex functions of SCs in skin physiology and pathology beyond skin sensation and nerve repair deserve more attention and systemic research than they have received so far. For example, SCs promote wound healing, disseminate infection in leprosy, support the growth of neurofibromas/schwannomas and facilitate/accelerate the growth and invasion of melanoma. Despite representing a major dermal cell population, comparatively little is still known about the role of SCs in other dermatoses. To quintessentially illustrate the opportunities that promise to arise from a new skin research focus on SCs, we focus on two dermatoses that are not traditionally associated with SCs, that is, psoriasis and atopic dermatitis (AD), since both show distinct SC changes along with continuous nerve fibre degeneration and regeneration, and an impact of denervation on skin lesions. Specifically, we critically discuss the hypothesis that repeated activation of the SC repair programme occurs in and contributes to psoriasis and AD and delineate experimental approaches how to probe this clinically relevant hypothesis.

A cross-sectional study of variations in the biophysical parameters of skin among healthy volunteers.

BACKGROUND: Biophysical parameters of skin such as trans-epidermal water loss (TEWL), hydration, elasticity, pH, and sebum reflects it functional integrity. Advances in technology have made it possible to measure these parameters by non-invasive methods. These parameters are useful for the prediction of disease and its prognosis. It also helps in developing new skin care products according to various skin types, and to evaluate, modify, or compare the effects of existing products. AIM: The aim of the study was to measure, evaluate, and analyze variations in biophysical parameters at pre-selected skin sites in healthy Indian volunteers, across different age groups and gender. METHODS: The study was conducted among 500 healthy Indian volunteers, between 5 and 70 years of age, in the outpatient department of dermatology at Sir T. Hospital, Bhavnagar. Biophysical parameters such as TEWL, hydration, elasticity, and sebum content was measured on four pre-selected body sites by a Dermalab instrument (Cortex Technology, Denmark). The skin pH was measured with a sensitive pH probe (BEPL 2100). RESULTS: All parameters were higher in males compared to females, except for sebum content, which was equal in both genders. Transepidermal water loss and hydration was lower in middle and older age groups. The skin pH showed no statistically significant difference with age. Sebum content was higher in middle and older age groups. The nose had the highest sebum content across all age groups. The forehead showed higher median values of TEWL and hydration compared to other sites. Though elasticity has highest value on forearm, only leg region showed statistically significant value. LIMITATIONS: The present study was confined to a single geographical area, so the effect of environment changes could not be judged accurately. Seasonal variations were not studied as it was a cross-sectional study. CONCLUSION: Skin properties vary with age, gender, and location on the body. This knowledge will help to create a database of these parameters in the Indian population. It would assist in the diagnosis of various clinical conditions and monitor therapeutic response.

Lucio's leprosy: a clinical and therapeutic challenge.

Leprosy has been a challenge in different areas of medicine; in underdeveloped countries it remains a public health problem, in which the social and economic problems facilitate the disease persistence. The diagnosis and consequently the treatment are delayed due to the clinical polymorphism of leprosy, which especially at the beginning the manifestations are not as evident, as is the case of diffuse lepromatous leprosy. This favors the disabilities and the development of the reaction episodes. Fortunately, reaction episodes have decreased with the use of multidrug therapy, and better control of the type 2 reactions has been managed with the use of thalidomide, as in Lucio's phenomenon.

Lucio's leprosy: a clinical and therapeutic challenge

Leprosy has been a challenge in different areas of medicine; in underdeveloped countries it remains a public health problem, in which the social and economic problems facilitate the disease persistence. The diagnosis and consequently the treatment are delayed due to the clinical polymorphism of leprosy, which especially at the beginning the manifestations are not as evident, as is the case of diffuse lepromatous leprosy. This favors the disabilities and the development of the reaction episodes. Fortunately, reaction episodes have decreased with the use of multidrug therapy, and better control of the type 2 reactions has been managed with the use of thalidomide, as in Lucio's phenomenon.

Sensitive skin: an overview.

Sensitive skin is less tolerant to frequent and prolonged use of cosmetics and toiletries. It is self-diagnosed and typically unaccompanied by any obvious physical signs of irritation. With the change in lifestyle and also with increased opportunity to use many new brands of cosmetics and toiletries, there has been an increase in females complaining of unique sensation in their facial skin. Sensitive skin presents as smarting, burning, stinging, itching, and/or tight sensation in their facial skin. The condition is found in more than 50% of women and 40% of men, creating a sizable demand for products designed to minimize skin sensitivity. Good numbers of invasive and non-invasive tests are designed to evaluate and predict the sensitive skin. Management includes guidelines for selecting suitable cosmetics and toiletries in sensitive skin individuals.

Dressing spray enhances the adhesive strength of surgical dressing tapes.

BACKGROUND: The use of surgical adhesive tapes after minor surgical and dermatologic operations is widespread. Their use reduces the wound tension and separation and they ultimately improve the postoperative scar. The most commonly used wound adhesives to enhance the adhesiveness of the surgical tapes, are tincture of benzoin and mastisol. AIM: The purpose of the present study is to demonstrate the role of adhesive power of dressing spray with the adhesive tape application on the skin, which is widely used in clinics after the skin closure. METHODS: Fifteen volunteers who were chosen among the medical personnel of the hospital comprised the study group. The skin of the flexor aspect of the 1/3 middle forearm of the subjects was used as the procedure region. The data is collected in the first, second and eighth days of the study. At the first stage of the study, an adhesive wound closure tape was applied to the skin without any compound of adhesives (group A). In the second and third stages, a thin coat of transparent film dressing spray (group B) and an adhesive compound of tincture of benzoin (group C) were applied to the skin before the adhesive tape placement, respectively. Different values of weights ranging between 50-900 gm were hanged by hooking into the center of the adhesive tape. The weights that caused complete separations of the tape from the skin after exactly 20 seconds were recorded in all groups. The data was analyzed by using Friedman test in order to calculate statistical significance between groups A, B and C. RESULTS: The difference in adhesive power between control and groups B and C was found to be highly significant ( p CONCLUSION: The results indicated that dressing spray tested has an additional adhesive power besides its well known features and that it can be used as an efficient alternative material among other adhesive compounds.

GM-CSF activates regenerative epidermal growth and stimulates keratinocyte proliferation in human skin in vivo.

Granulocyte/macrophage-colony-stimulating factor (GM-CSF), an immunomodulator of hematopoietic cells, has also been shown to stimulate human keratinocyte proliferation in vitro and speed healing of wounds in the skin of lepromatous leprosy patients. In this study we have examined the in vivo effects of recombinant human GM-CSF on epidermal keratinocyte proliferation and on expression of proteins marking regenerative epidermal growth. Skin biopsies from GM-CSF injected cutaneous sites were obtained between 1 and 6 d following administration of 7.5 or 15 micrograms of the growth factor. Activation of keratinocyte proliferation, quantified as the expression of the Ki67+ nuclear antigen, was noted 1 d following GM-CSF administration. A regenerative epidermal phenotype, demonstrated by immunohistochemical staining of cellular proteins involucrin, filaggrin, and keratin 16, was similarly noted as early as 1 d following GM-CSF injection. This phenotype persisted as late as 6 d post-injection. These results suggest that GM-CSF injection into human skin induces keratinocyte proliferation as well as regenerative differentiation of the epidermis. To date no other cytokine has been shown to be mitogenic for human keratinocytes both in vivo and in vitro or to alter keratinocyte differentiation along the "alternate" or regenerative pathway.

Heat (shock) and the skin.

Whereas hyperthermia has long been used in dermatology for the therapy of diseases as diverse as syphilis, gonorrhea, psoriasis or melanoma, the understanding of the biological effects of heat shock on the skin attracts new interests to an old field. The proteins induced by heat (stress, or heat shock proteins) appear to play a general role in protection from cellular injury and eventually in the natural defences from solar radiation. On the other hand, these ubiquitous proteins may also be involved in the immunopathology of diseases such as systemic lupus erythematosus or leprosy.

Minimum temperature felt as hot (MTH)--a new concept for grading the loss of temperature sensation in leprosy patients.

In order to grade the loss of the temperature sensation in the skin of leprosy patients, a newly designed instrument called the Temperature-Sensation-Testing-and-Grading device has been employed to determine the minimum temperature felt as hot (MTH) at the skin area. The MTH in normal subjects was observed to vary from one region of the body to another; it was generally higher on the distal parts of the extremities compared to the proximal parts; and it was also higher on the lower extremities compared to the upper ones. The abdomen and the back generally had the lowest values. There were no variations according to age (11-80 years) or sex and no differences on symmetrical sites of the body. The MTH value, however, showed a dependence on the environmental temperature, the values being lower at low environmental temperatures and higher at high environmental temperatures. But at the same site and the same environmental temperature, the MTH value was found to be almost constant. Different individuals had different MTH values at the same body site and even at the same environmental temperature. The unaffected skin of leprosy patients showed values comparable to the controls. At the leprosy lesions, however, the degree of sensory loss could easily be determined in comparison with the MTH at the contralateral/adjoining unaffected skin. Out of 54 leprosy patients, 7 patients had no sensory loss; in 27 patients the loss varied between 1 degree C and 20 degrees C; while in 20 patients the loss was complete--they could not perceive even 50 degrees C as hot.(ABSTRACT TRUNCATED AT 250 WORDS)

Cutaneous tissue repair: basic biology considerations. I

Wound repair of the integument is reviewed in the context of new developments in cell biology and biochemistry. Injury of the skin and concomitant blood vessel disruption lead to extravasation of blood constituents, followed by platelet aggregation and blood clotting. These events initiate inflammation and set the stage for repair processes. The macrophage plays a pivotal role in the transition between wound inflammation and repair (granulation tissue formation), since this cell both scavenges tissue debris and releases a plethora of biologically active substances that include growth factors. Although concrete evidence is lacking, growth factors are probably at least partially responsible for the angiogenesis and fibroplasia (granulation tissue) that gradually fill the wound void. If the epidermal barrier is disrupted during injury, reepithelialization begins within 24 hours and proceeds first over the margin of residual dermis and subsequently over granulation tissue. The signals for angiogenesis, fibroplasia, neomatrix formation, and reepithelialization in wound repair are not known, but a number of possibilities are discussed. Matrix remodeling is the last stage of wound repair and gradually increases the scar tensile strength to 70% to 80% of normal skin.

Transport into and within the skin / ver

Developments in recent years permit us to state the following principles which relate to percutaneous obsorption. The entire stratum corneum functions as the rate limiting barrier in the skin. For penetration from weak solutions flux is directly proportionbal to the concentration of the penetrat in the solution which is presented to the cutaneos surface. Flux increases as the mobility of the penetrat in the stratum corneum (diffusion constant) increases. Flux decreases as the thickness of the membrane increases. When concentrations in the presenting solution reach higt values flux is not proportional to concentratio. Flux through dermal tissue is much more rapid than flux through the stratum corneum. For substances which penetrate relatively rapidiy the major pathway throug the skin for steady state conditions is directy thorough the cells of the stratum corneum. For very slowly penetratingsubstances shunts, e.g., the appendages may be the major pathway. Strongly polar and strongly non polar molecules probably travel via different molecular pathways.